This invention relates to latching mechanisms for use in vehicle seat hinge assemblies, and more particularly to latching mechanisms for use in vehicle seat hinge assemblies wherein the seatback of the vehicle seat can assume a forwardly folded, dumped position.
Passenger vehicles, especially combined passenger and utility type vehicles, particularly mini vans, commonly have rear seats (second row and third row) and also perhaps a front row passenger seats, the seatbacks of which each can fold forwardly to a substantially horizontally disposed forwardly folded dumped position, to thereby allow for ingress and egress of passengers to the area behind the folded seats, to facilitate carrying of large or lengthy objects inside the vehicle, and to provide a convenient substantially horizontal flat surface for articles that might be used in a vehicle such as briefcases, laptop computers, food and drinks, and the like.
It is also common in a pickup truck having front and rear seats, for the rear seats to have seat cushion members that tilt upwardly and rearwardly from a substantially horizontal occupiable position to an upright stowed position, thereby to permit the storage of cargo between the front and rear seats when the seat cushion is in its upright stowed position.
Also, it is known to have reclining vehicle seats that have a seatback pivotally mounted on a seat cushion so as to be reclinable from an upright occupiable position to a single predetermined reclined position.
In any of the above discussed vehicle seat arrangements, the vehicle seat typically comprises a pair of vehicle seat hinges, with each vehicle seat hinge having a mounting plate securely attached to a vehicle seat cushion and a sector plate securely attached to a vehicle seatback. Pivotal movement of the seatback member with respect to the seat cushion member is precluded by means of a selectively operable latch that provides a substantially no-chuck latching in each of the two relative angular positions of the seat cushion and the seatback. Commonly, such latches have a manually operable pawl pivotally mounted on the mounting plate for engagement with a cam member also pivotally mounted on the mounting plate. The cam member frictionally engages a first cam surface disposed on the sector plate when the seatback member is in its upright occupiable position and frictionally engages a second cam surface disposed on the sector plate in angularly spaced relation from the first cam surface, when the seatback member is in its forwardly folded position, stowed position, or reclined position, as the application may require. The first and second cam surfaces are spaced apart on the upper sector plate typically by a distance of several inches in order to accommodate the pivoting of the seatback member through an included angle of up to perhaps 120 degrees. Accordingly, a relatively large sector plate is required to provide substantially no-chuck latching in the two positions of maximum angular separation. The use of such large sector plates is highly undesirable as it is difficult to fit them within the limited space envelope allotted in modern vehicle seat hinge designs.
Canadian published Patent Application No. 2,286,048, published Oct. 15, 1998 in the name of Smuk, for a Single Control Handle Release Mechanism For Use With A Vehicle Seat discloses a vehicle seat wherein the seatback folds forwardly over the seat cushion, with the angular position of the seatback with respect to the seat cushion in both the upright position and the forwardly folded dumped position being determined by a stop-pin engaging a curved slot in the rotational control plate. It can be seen that the portion of the rotational control plate that contains the slot is undesirably wide in order to accommodate the curved slot.
In U.S. Pat. No. 6,102,771, issued Jan. 11, 2000 to Shea, for a Seatfold Mechanism, a folding seat assembly has a seat bottom secured to a pivot bracket with the pivot bracket being pivotally mounted on a mounting bracket that is secured to the floor of the vehicle. The seatback is pivotally mounted to the pivot bracket. The seat bottom pivots rearwardly and upwardly from a horizontal occupiable position to an upright stowed position where it contacts the seatback, to permit storage of cargo between the front seat and rear vehicle seats. A doubler plate is engaged by a spring detent mechanism to latch the seat bottom in its seating position and when in its folded upright position. The pivot bracket and the doubler plate are both undesirably large in order to be able to engage the spring detent latching mechanism in both the occupiable and stowed position of the seat cushion member.
It is an object of the present invention to provide a two position latch for use on a vehicle seat hinge.
It is another object of the present invention to provide a two position latch for use on a vehicle seat hinge, which latch is significantly smaller than prior art latches two position latches having similar ability.
It is another object of the present invention to provide a two position latch for use on a vehicle seat hinge, which latch more easily fits into a limited design space.
In accordance with the present invention there is disclosed a latching mechanism for use in a vehicle seat hinge assembly having a seatback hinge plate mountable on a seatback member and a seat cushion hinge plate mountable on a seat cushion member. The seatback hinge plate is pivotally connected to the seat cushion hinge plate for pivotal movement about a hinge pivot axis between a first angular orientation corresponding to a substantially upright position of the seatback member, and a second angular orientation corresponding to a forwardly folded position of the seatback member. The latching mechanism comprises a guide means disposed in the seat cushion hinge plate and a stop means disposed adjacent the guide means. A link arm member has an elongate axis and a first end, a second end, and a follower member disposed adjacent the second end so as to be engaged in retained sliding relation by the guide means. The link arm member is pivotally mounted adjacent the first end on the seatback hinge plate in spaced relation from the pivot axis for movement about a link pivot axis between a first latchable position corresponding to the first angular orientation and whereat the follower member contacts the stop means, and a second latchable position corresponding to the second angular orientation and whereat the follower member contacts the stop means, and through an intermediate unlatching position corresponding to an intermediate position between the first and second angular orientations and whereat the follower member is removed from contact with the stop means. A latch means is mounted on the seat cushion hinge plate for selectively holding the follower member of the link arm member in restrained contact with the stop means, to thereby retain the seatback hinge plate in either of the first and second angular orientations.
Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter of which is briefly described hereinbelow.